Answer to Question #301980 in Statistics and Probability for toodles

Question

Mrs. Paul wants to test that claim that, on average, her students' average mark is 85. She pulls the records of 100 per past student over a three-year period. The grades are inputted into MINITAB for analysis. Exhibit 1 below shows the results of an analysis carried out on the data obtained.

Exhibit 1

One-Sample Z: Level I/II

Test of mu = 85 vs mu not = 85 The assumed sigma = 15.0

Variable N Mean StDev SEMean Z P

Students Score 100 75.4 12.99 * ** ***

i. Calculate the SEMean]

ii. Construct a 98% confidence interval for the population scores of Mrs. Paul’s students.

iii. State the null and alternate hypotheses for this test.

iv. Calculate the missing value ** and use tables to approximate the value of ***.

v. Using a 1% level of significance, state the decision criteria for this test

vi. State the conclusion for the test and why